Clock escapement



Jan. 6, 1925.

c. H. BRIGDIEN CLOCK ESCAPEMENT 5 Sheets-Sheet 1 Filed Sept. 3, 1921 Jan. 1925. 1,522,099

c. H. BRIGDEN CLOCK ESCAPEMENT Filed Sept. 3, 1921 3 Sheets-Sheet 2 CLOCK ESCAPEMENT Filed Sept. 8, 1921 3 Sheets-Sheet 3 Patented Jan. 6, 1925.

UNITED STATES CHARLES H. BRIG-DEN, OF 'WALTHAM, MASSACHUSETTS.

CLOCK ESCAPEMENT.

Application filed September 3, 1921.

To all whom it 72mg concern:

Be it known that I, CHARLES H. BRIGDEN. a citizen of the United States, residing at Waltham, in the county of Middlesex and State of h lassachusetts, have invented new and useful lmproven'ients in Clock Escape ments of which the following is a specification.

This invention relates to clock escapements more particularly designed for timepieces in which extreme accuracy is desired. In such escapements it is desirable to eliminate all parts subjected to friction. since friction is a factor subject to wide fluctuations from time to time dueto varying lubrication and surface conditions of the contacting parts.

This invention provides a construction wherein the usual crutch and pallet bearings are entirely eliminated so that friction is greatly reduced and in its preferred forms requires no lubrication between the pallet and the escape teeth.

Further this invention provides a mechanism in which separate means for looking the escape wheel is unnecessary, eliminating the complications produced by the presence of such parts and the friction inherent therein.

It is also important that the force act ing on the pendulum to trip the pallet and to permit rotation of the escape wheel'shall be uniform. \Vhile weights for (JlYlllfl the entire movement may be mounted so as to exert. a substantially uniform force for 1 this purpose, it is not always convenient or possible to employ them and the force of the volute springs commonly used varies considerably dependingon the extent of. winding and on frictional engagement be co nivoluti onsi,

This invention provides mechanism by which a variable propelling power such as a spring may be caused to exert a substan tially constant force to actuate the pendulum by inter-posing a leaf spring therebetween. this spring being flexed by the propelling power to a substantially constant extent. at each actuation and exerting its force directly against the pendulunr This leaf spring also furnishes the pivotal axis of the pallet so that no friction bearings therefor are required.

Further this invention provides a construction adaptable to a solid or divided "pallet and with most of its desirable char Serial No. 498,222.

acteristics to pin wheel escapements and in connection with anchor pallets.

For a more complete understanding of this invention, together with further objects and advantageous details and combinations of parts reference may be had to the accompanying drawings in which Figure 1 is a front elevation of one form of escapement, the pendulum being shown 111 mid position.

Figure 2 is a side elevation of the same.

Figure 3 is a view similar to Figure 1. but showing the pendulum swung to one side, the position of the parts being somewhat exaggerated for clearer showing.

Flgure l is a perspective of the pallet.

Figures 5, 6. and 7 are front elevations of modified constructions.

Figure 8 is an elevation showing an ap plication of the invention to a pin wheel escapement.

Figure 9 is a side elevation of the same.

Figure 10 is a perspective of one form of pallet suitable for pin wheel escapements.

Figure 11 is a perspective of an anchor pallet.

Figure 12 is a fragmentary detail showing the relations of escape teeth to the pallet points in the construction shown in Figure 11.

Referring more particularly to Figures 1 to t at A is shown a supporting plate for the clock movement through which passes a shaft 1 forming part of the gear train driven by a motor of any suitable description and which has fixed at its outer end an escape wheel 2. As shown this escape wheel has five teeth 3 thereon. This is the minimum number which can be used satisfactorily. but any higher odd number may be substituted.

Above the wheel 1 is fixed a block 4, forked at its lower extremity to receive between the forked portions and to be clamped therein the upper end of a leaf spring 5. it screw 6 may be used to clamp this spring in position. Somewhatbelow the screw 6 is fixed the upper end of a pendulum hanger '7. the space between the top of the hanger and the block 4 providing a section of unsupported spring furnishing a hinge joint for the pendulum. The lower end of the member 7 has fixed thereto a block 8 carrying a pin 9 transversely there of over which may be engaged a bifurcated hook 10 fixed to the upper end of the pendulum rod 11. the pendulum weight being indicated at 12.

Beneath the block 7 the spring 5 is attached to the upper end of a pallet 13. the portion of the spring between the pallet and the block 7 providing an axis about which the. pallet may oscillate. The lower end ot this pallet is provided with an opening 14- and projecting part way across this opening at the top and hottonrare the pallet points or stones l5 and 16. These stones are positioned so as to bev engaged alternateh by teeth of the escape wheel above and-below the shaft- 1. Above the opening 14 the pallet is provided with opoositely extemling arms l? and and tixeu in position to be engaged at certain times by these :ll'hls are a pair ol lnmking studs or stops 19 and 20. These parts are so proportioned that when one ot the points or stones 15 and 16 is en gaged by an escta xnnent tooth 3. rotation ot the escape wheel due to the clock motor urges the pallet laterally to bring one of the arms 17 or 18 into engagement with its bank ing stud, the. spring 5 flexing for this purpose. The flexing of this spring imparts a torce tending to swing the pendulum in the same direction as the pallet has been moved. the pallet being carried therewith. Suiticientswing of the pendulum in response to this force flexes the spring 30 in the opposite direction and moves the pallet about the banking stud so as todisengage the pallet point trom the escapement tooth which thereupon escapes theretron'i. The tooth on the opposite side of the axis of the shaft 1 thereupon engages the opposite palietpoint throwing the pallet to its extreme. lateral position in contact with the other banking stud. This action flexes the spring 5 in the opposite direction and imparts a thrust tending to swing the pendulum in the same di rection. This pallet point remains in contact with the escapelnent tooth; until the pei'idulum has swung nearly to its extreme position in this direction. (its inertia causing a turther motion after the "hange in direction of the force exerted by the spring) whereupon it is removed from the path ot the tooth which is then free to move until the wheel stopped by engagement of a tooth with the tirst pallet point whereupon thc cycle ot operations is repeated.

it will thus be seen that the force applied to swing the pendulum is exerted through the leai spring 5 which is llexed the same amount at each actuation and therefore exerts a uniform t'orce tending to swing the pendulum at each actuation \.'arying power of the driving motor merely changing the pressure exerted against th banking studs. It is tlSO seen that the spring turnishes a pivotal connection for the pallet which has no other bearings except against the banking stud or stops. The pallet thus has a.

bodily movement between the banking studs, pivoting about its suspension axis or center in the spring 5, and it also rocks about the banking studs in turn as the pei'idulum swings until the escapement wheel is re leased and drives the pallet against the other stud.

ln Figure 5 a modified construction is shown in which the pendulum is hung from the lower end (it a yoke 27, this yoke being supported by a leaf spring 28 from a block 29 within the yoke and made fast to the frame plate A. Projecting from the upper end of the yoke 27 a second leaf spring 30 to the. upper end of which is fixed the lower end of the pallet 31. This pallet -31 has a pair oi points or stones 32 herein shown as tormed oi circular pins flattened on the side facing the escape whee 33. The upper end of this pallet is termed as an arm 3-4 which projects between a pair of banking studs 21;") and 3G. The action of this mechanism is substantially the same as that previously described. the escape wheel 2): acting alternately against the points 32 and brin; in;

th arm 34 alternately against the studs 35 and 3(3. This action flexes the. spring 30 alternately in opposite directions to impart swinging motion to the pendulum. this swinging motion acting through the spring 30 to move the pallet sufficiently to disen gage the points 32 alternately from the escape wheel. In this case, however. the pendulum is supported from. below the pallet instead of above as in the other form.

In l gure (i is shown a further modifica- "ion in which the pendulum is hung at a point above the pallet substantially as shown in figures l to l. the pendulum rod being here indicated a t 37 fixed to a leaf spring 3t made tast at $19 and having tixed at its lower end beneath the attachment to the pendulum. the upper end oi the pallet l0. 'lhis pallet provided with points or studs ll and the lower end thereot' is prolonged to t'orm an arm 42 which vibrates between the stops or banking studs 43 and ll. the action of this arm being identical with that in the t'orm shown in Figure ln l igure T is shown a further modification in which the pendulum 50 supported at the lower end of a spring 5t iixed at its upper end at 52. the pendulum extending above the point 52 and carrying the lower end of a spring 5 5. The upper end of spring :33 attached at 54 to a pallet; 55 having points or studs 5(3 thereon engageable by the teeth of the escape wheel 57. l lxteuding laterally of the pallet 55 are a pair of stop arms 58 and 59 which may impinge against banking studs (it) and 61. As herein shown each banking stud has passed therethrough an abutment screw as 62 and (i and adjacent the inner end thereol is a lixed member (34, and 65. \Vith this form of the'device. swinging of the pendulum to release the pallet stones causes considerable movement of the abutment arms 58 and 59 against the banking studs. By adjustment of the screws 62 and 63 resistance to this motion may be varied at opposite ends of the traverse of the pallet and by proper adjustment the pendulum may be regulated asymmetrically, that is, so that it may swing at equal distances in either direction.

In Figures 8, 9, and 10 is shown another form of deviceparticularly designed for pin wheel escapements. In this case the pendulum is shown at 70, the upper end thereof being made fast to a leaf spring 71 lixed at its upper end at 72 to part of the clock frame, the spring '71 projecting below the attachment of the pendulum thereto and being made fast to the upper end of the pallet 73. This pallet 3 has an opening 'T-l: therethrough, and projecting from opposite directions partly across this opening are the points or stones 75 and 76. A pin escape wheel is shown at 7'7 fixed to a shaft or arbor 78. This wheel has pins 79 extending from one face thereof which are engageahle by the points 7 5 and 76. In this form the points or stones 75 and 76 have inclined upper faces'SO and 81 on which the pins T9 impingathese faces being inclined in opposite directions so as to urge the pallet alternately in opposite directions. This form of the device requires lubrication since there is rubbing contact between the faces and 81. and lb is alsonecessary to employ rest nibs or stops 82 and 83 at the ends of the points against which the pins 79 rest be'tore the points are moved to disengage them by n'ieans of the swinging of the pendulum. ll hile these stop lugs or nibs may be sulficient in themselves to insure against release of the pins except by the motion of the pendulum, it might also be desirable to employ fixed banking studs or abutments 8t and 85 conta ted alternately by arms 86 and 87 projecting laterally from the pallet as in the other forms herein shown.

l Vhile in this form the pendulum is shown as pivoted above the pivot of the pallet, it quite evident that constructions similar to those in Figures 5 and '7 might be employed wherein the pivotal point of the pendulum below that of the pallet.

ln Figures ll and 12 is shown another orm of the. invention as applied to anchor allets. in this form the pallet 90 is supported at the end of a leaf spring 91 which may be attached to the pendulum in the manner of any of the deviies above described, herein shown this being of the type wherein this connection is above the connection of the pallet. In this form inclined taces 92 and 93 are provided on the pallet points for engagement with the escapement teeth as is usual with anchor pallets, and for insuring against premature release of the teeth, rest nibs 92'. 93' and arms 9% and 95 contacting vith banking studs 96 and 97 have been indicated. The action of this device is substantially the same as in the pin wheel escapement, the teeth of the escapement wheel riding on the inclined faces 92 and 93 and urging the pallet alternately in opposite directions whereby the spring 91 is tiered and vibrating impulses transmitted to the pendulum by the motion of which the engagement between the pallet points and the escape teeth successively released.

ll liile the various forms of the invention above described afford mechanisms which are extremely accurate in operation it will be noted that they also eliminate many of the parts usually found necessary in escapement mechanisms whereby the cost of the mechanisms may be considerably reduced.

Having thus described certain embodiments of this invention it should be evident to those skilled in the art that many modilica ions and changes might be made without departing from the spirit or scope of the invention as defined by the appended claims.

1 claim:

l. A mechanism of the class described. comprising an escape wheel, a pallet cooper- 'r j with said wheel. a pendulum for actune" said pallet, and a spring carrying said pallet and actuating said pendulum.

2. A mechanism of the class desrribed comprising an escape wheel, a. pallet co- ;.i-,.rating with said wheel. a leaf spring supporting said pallet, and a pendulum desubstantial swinging impulses from ring and actuating said pallet to successiveiy release teeth of said escape wheel.

3. 1 mechanism of the class described com 'n'ising an escape wheel, a pallet cooperating with said wheel, a leaf spring carrying said pallet and forming a pivotal center therefor, fixed banking elements against which said pallet contacts alternate ly by pressure of said escape wheel, flexing said spring alternately in opposite directions. and a pendulum actuated by the flexing of said spring to swing and move the pallet to successively release teeth of said escape wheel.

l. A mechanism of the class described COlUpl'lSlDg an escape wheel, a pendulum. and a rockable and bodily movable pallet, the bodily movement of said pallet imparting swinging impulses to said pendulum. and said pendulum acting by its swinging to rock said pa let to successively release teeth of said escape wheel.

A n'vchanism of the class described comprising an escape wheel, a pendulum, and a pallet cooperating with said escape wheel and pivotally carried by said pendulum.

mechanism of the class described till comprising an escape wheel, a pendulum, and a pallet cooperating with said escape wheel and pivotally carried by said pendulum and bodily movable therewith.

7. A mechanism of the class described comprising an escape wheel, a pendulum, a pallet cooperating with said escape wheel and mounted on said pendulum, and stops for limiting the movement of said pallet.

8. A mechanism of the class described comprising an escape wheel, a pendulum, a pallet cooperating with said escape wheel and mounted on said pendulum, stops for limiting the movement of said pallet and over which said pallet moves, and means for independently adjusting the resistance to relative motion between said pallet and each stop.

9. A mechanism of the class described comprising an escape wheel, a pendulum, and a pallet cooperating with said escape wheel carried and actuated by said pendulum to successively release teeth of said escape wheel.

10. A mechanism of the class described comprising an escape wheel, a pendulum, and a pallet spring-supported from said pendulum and cooperating with said escape wheel.

11. A mechanism of the class described comprising an escape wheel, a pendulum, a pallet spring-supported from said pendulum to move therewith and to rock relative thereto, and fixed banking elements against which said pallet is rocked alternately by pressure from teeth of said escape wheel, whereby said spring is flexed to impart swinging impulses to said pendulum and the movement of said pallet effected by the swinging of said pendulum acts to successively release teeth of said escape wheel.

12. A mechanism of the class described comprising an escape wheel, a pendulum, a pallet, a leaf spring connecting one end of said pallet with said pendulum and providing a center of oscillation therefor outside the center of oscillation of said pendulum, and a pair of fixed banking elements positioned at either side of said pallet to limit its oscillation.

13. A mechanism of the class described comprising an escape wheel, a pendulum, a pallet cooperating with said wheel, and a flexible spring for imparting substantial swinging impulses to said pendulum and also serving as a pallet axis.

14. A mechanism of the class described comprising an escape wheel, a pendulum, a pallet cooperating with said wheel and carried by and movable relative to said pendulum, and stops to limit the movement of said pallet to prevent release of said escapement wheel until said pendulum has sub stantially completed its swing in either direction.

15. A mechanism of the class described comprising an escape wheel, a pallet having faces for alternate engagement with teeth of said wheel and actuated to successively release said teeth, and a rest nib on each face to prevent premature release of said teeth.

16. A mechanism of the class described comprising an escape wheel, a pendulum, a spring forming an axis for said pendulum, a pallet cooperating with said wheel, a spring forming an axis for said pallet and through which swinging impulses are imparted to said pendulum, and means to limit the swing of said pallet acting to prevent release of said wheel before the substantial completion of swinging in either direction of said pendulum.

17. In a clock having a motor, an escape wheel driven by said motor, a pallet cooperating with said wheel, means for controlling said pallet, and means by which impulses of uniform force are imparted to said controlling means regardless of fluctuations in the force of said motor.

18. A mechanism of the class described, comprising an escape wheel, a pallet cooperating with said wheel, a pendulum, means independent of said pallet for pivotally supporting said pendulum, and a spring interposed between said pallet and pendulum, said spring being tensioned by movement of said pallet by said escape wheel to swing said pendulum and being tensioned by the swinging of said pendulum to move said palletto release said escape Wheel.

19. A mechanism of the class described, comprising an escap wheel, a pallet cooperating with said wheel, a pendulum, means independent of said pallet for pivotally supporting said pendulum, and a spring alternately tensioned by movements of said pallet and pendulum to impart movement to said pendulum and pallet respectively to cause periodic release of said escape wheel.

20. A mechanism of the class described, comprising an escape wheel, a pallet cooperating with said escape wheel, means for controlling said pallet to alternately release and stop said escape wheel, and a spring tensioned to a uniform extent regardless of fluctuations in force applied to said escape wheel for actuating said controlling means.

21. In a mechanism of the class described. an escape wheel, a pallet cooperating with said escape wheel and having a pair of inclined faces engageable alternately by teeth of said wheel and by which engagement swinging impulses are imparted to said pallet, a rest nib at one side of each inclined face to stop the pallet tooth riding on the corresponding face, and a pendulum deriving swinging impulses from the swinging impulses of said pallet acting to move said pallet further to move said rest nibs out of engagement with said teeth.

Ill

22. In a mechanism of the class described, an escape wheel, a pallet cooperating with said escape wheel and having a pair of inclined faces engageable alternately by teeth of said wheel and by which engagement swinging impulses are imparted to said pallet, a rest nib at one side of each inclined face to stop the pallet tooth riding on the corresponding face, a spring tensioncd by the swinging of said pallet, and a pendulum actuated by said spring and acting at the latter portion of its swing in each direction to reversely tension said spring to rock said pallet and release a rest nib, thereby permitting an escape tooth to engage the opposite pallet face and further reversely ten- CHARLES H. BRIGDEN. 

